According to their species gantry axles are especially used in low-platform autobuses where it is important to dispose the vehicle bottom low enough so that the passengers can comfortably enter from the sidewalk into the omnibus. It is to be taken into consideration here that the omnibus has sufficiently wide gangway available and, at the same time, does not fall short of ground clearance for running over obstacles.
DE 196 04 730 A1 discloses a gantry axle for low-platform autobuses in which the gantry transmission is driven, via an axle shaft, by a differential gear unit, two spur gears being situated between the input pinion and the output spur gear whose axes of rotation are disposed at the same height as the axis of rotation of the input pinion in order to obtain a power split on the input pinion to minimize the diameter and width of the input pinion. The gantry spacing between the axis of rotation of the input pinion and the axis of rotation of the output spur gear cannot be further enlarged since this would need a further enlargement of the diameter of the intermediate wheels which does not make a tying of the spring carrier possible in the usual manner. The ground clearance of a low-platform axle is determined by the opposition of the axis of rotation and the diameter of the crown wheel of the differential gear unit.
The published DE 21 16 441 discloses, the same as in DE 196 04 730 A1, an axle transmission for motor vehicles with a gantry axle in which the input pinion, is disposed flush with the intermediate wheels and stays in a split power operative connection with said intermediate wheels, the intermediate wheels consisting of one first spur gear and one second spur gear which are non-rotatably interconnected, the first spur gear being connected with the input pinion and the second spur gear with an output spur gear, the output spur gear driving the vehicle wheel. The axes of rotation of the intermediate shafts and the axis of rotation of the axle shaft must be on a common plane, the pinion shaft being radially movably supported on all sides in order to improve further the contact pattern of the tooth flanks.
The problem on which this invention is based is to provide a gantry axle, in particular for low-platform vehicles such as city autobuses, in which a sufficient ground clearance exists and the gantry spacing, compared to the prior art, is enlarged without detracting from the possibility of connecting of the gantry axle to the vehicle chassis.